Process of recovering sulfurous oxid.



.PATENTED AUG. 28, 1906. F. R. CARPENTER.

PROCESS OF REGOVERING SULPUROUS OXID. APPLICATION FILED JUNE 19, 1905.

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'U'Ni'rirn STATES PATENT OFFICE.

FRANKLIN R. CARPENTER, OF DENVER, COLORADO PROCESS OF RECOVERING SULFUROUS OXID.

Specification of Letters Patent.

Patented Aug. 28, 1906'.

Application filed June 19, 1905. Serial No." 266.050.

To all whom it may concern/.

Be it known that I, FRANKLIN R. CARPEN TER, a citizen of the United States, residing in Denver, in the county of Denverand State of Colorado, have invented certain new and useful Improvements in Processes of Recovering Sulfurous OXid from Furnace-Gases, of which the following is a specification.

In calcining and smelting sulfid ores there are contained in the gases given off by the furnaces largequantities of sulfurous oXid, (802.) The usual practice is to discharge such furnacegases into theatmosphere, with the result that all vegetation'in the surrounding country is destroyed; The presence of this gas in the atmosphere is also injurious to animal life in the region in which the furnace is located.

The principal objects of my invention are, first, to prevent the discharge of this injurious as into the atmosphere, and, second, to colect and concentrate it for further use, either for the purpose of obtaining sulfur therefrom or further treating it to produce sulfuric acid,

or for other purposes in which sulfur or its -it in such manner that it may be further treated with facility for the manufacture of 40 sulfur, sulfurous acid, or sulfuric acid.

In carrying out my process the furnacegases are first conducted through a flue of considerable length and size in which dust or solid particles mechanically carried over will be largely deposited and collected. This flue being ofrconsiderable size and length will also serve to reduce the temperature of the gases as they pass tlrough it approximately to the temperature of the atmosphere, and to aid in the.cooling of the gases 1 preferably spray water into the flue at any desired point or points, and this also serves to moisten the gases and facilitate the refrigeration, absorption, and-deposit of sulfurous oxid in the fur= ther treatment of the gases which pass from the'flue to a refrigerating chamber in which the gases are brought into contact with surfaces maintained at a low temperature by the circulation of'brine, ammonia, sulfurous oxid, or-other refrigerant.

proximately 0 centigrade, and the sulfurous oXid contained in the gases is largely absorbed by the watery vapor, and as the watery vapor is congealed it will entrap the sulfurous oxid,

and t us separate it from the fixed gases. The metallic vapors in the gases are also condensed; but this feature of the process need not be especiallyconsidered, as it is only inci dental to the main purpose of my invention,

which is the recovery of sulfurous maid, and the process is conducted with especial reference to such recovery. The cooling of the gases is gradual and before they are cooled down to approximately 0 Centigrade most of the sulfurous oXid will be absorbed. If the cooling of the gases be continued until their temperature is lowered to minus 10 centigrade, practically all of the sulfurous oxid will be separated, some of it beingre- 8o duced to a liquid.

While the furnace-gases naturally contain aqueous vapor, I prefer to add water by sprayingit in the flue, as before stated, in

order to more thoroughly moisten the gases and facilitate the absorption of the sulfurous. maid in the refrigerating-chamber.

Wherever in the above description I have referred to sulfurous oXid (S8,) 1 also intend to include sulfuric oXid, (SO which is usu- 9o ally present in variable quantities in the furnace-gases. Both of these gases in the presence of water combine with it. and form, re-

spectively, sulfurous acid and sulfuric acid.

in the accompanying drawing l have shown, 9 5

partly inlelevation and partly in section, an apparatus which-will indicate what devices may be used in carryirn out my process.

A represents a metallurgical furnace from which a downtake B conducts the furnaceroo gases to the flue C, which should be of suflicient size and length to permit the larger solid particles mechanically carried over with the gases to settle as far as possible,while the gases are cooled down to approximately the temr0 5 perature of the atmosphere. By thus depos- In this chamber the 60 temperature of the gases is reduced to apiting the solid particles 1 am enabled to ob- 7 the refrigerating-chamber D broken away in order to indicate that only part of this chamber is illustrated, it being, as before stated, of considerable length in order that the gases may be gradually cooled and the sulfurous oxid completely absorbed before any of the gases are allowed to escape. The bottom of the chamber maybe formed, as shown, with channels by which the products nray be drained off or removed to one side.

At the end of the refrigerating-chamber D opposite that connected with the flue C is located an exhaust-fan E, which will aid the passage of the ases through the chamber and cause the ischarge of what has been called the fixed gases. The furnace-gases preferably enter the refrigerating-chamber completely saturated with moisture, which immediately begins'to condense and will precipitate like rain to the floor of the chamber and will be deposited like frost on the pipes. Solid particles in suspension in the gases, Whether they come as such from the furnace or Whether formed by solidification of metal vapors, will form centers for the condensation of the moisture and will also be caught mechanically .by the moisture when condensed and by both means will be separated from the gases and precipitated. As the gases pass farther into the chamber their The watery vapor beginning to condense on entering the refri crating-chamber will at once absorb the su fu rous and sulfuric oxids with which it is in contact, thereby forming sulfurous and sulfuric acids, and the power of absorption increases as the temperature is lowered toward the point at which the sulfurous and sulfuric oxids will themselves liquefy, so thatas the gases approach the discharge-opening of the refrigerating-chamber scares they will be completel absorbed by the condensed water and on y those gases will remainas such which are unaffected by any ordinary low temperature and which are harmless to life and vegetation.

As before stated, my process is conducted with special reference to the recovery of sulfurous oxid from furnaceases, and while it is true that metallic partic es and some other things are also collected, this is merely incident to my process, and my process is not conducted with special reference to the recovery of anything except sulfurous oXid or sulfuric oxid, which latter is usually present. The sulfurous oXid isabsorb'ed by the water, and this water containingthe sulfurous oxid may be further treated to produce sulfuric acid by the contact of other processes, or'it may be treated by well-known processes to obtain sulfur in solid form.

In the well-known contact-sulfuric-acid process the dust often resent in the gases in terferes greatly with t e" operation, audit is expensive to heat up .the inert gases which usually pass to the catalyzing substances. By my improvements the dust and inert gases are eliminated, and thus when the sulfur-gases, cleaned and concentrated by my process, are used in the contact process the cost of such process is greatly reduced. Again, it is not usually considered profitable to use the fumes from pyrrholite for the manufacture of sulfuric acid, althou h pyrrholite exists in great quantities througliout the whole Ap alachian region, while pyrite is scarce. %y my improvements the useless gases present in such pyrrholite fumes are eliminated and which ma thus be allowed to pass to the lead-chem ers or the catalyzers and used with economy.

What I claimis 1. The herein-described process of separat ing sulfurous oXid from furnace-gases, which gases dust or solid particles mechanically carried over from the furnace, refrigerating the tigrade to cause the sul rous oxid contained in the gases to be absorbed by the watery vapor therein and to be condensed or concentrated and deposited, separating the sulfurous oxid from the fixed gases and carrying off the fixed gases thus separated. I

2. The process herein described, consisting in gradually cooling the gases of furnaces burning sulfid ores, depositing solid particles mechanically carried over with the gases while they are being cooled, se arating sulfurous oxid from the fixed gases y absorbing away the unabsorbed or fixed tgases thus sep arated from the sulfurous oxi and then colonly rich sulfurous oxid gases are collected,

consists in first separating from the furnace- I10 gases thus cleaned'to a proximately 0 cen-' I it in water and refrigerating it, carrying lecting the sulfurous oxid thus separated and ing it, carrying off the unabsorbed or fixed concentrated. gases thus separated and then collecting the 3. The process herein described, which sulfurous oxld thus concentrated and sepaconsists in gradually cooling the gases of furrated from the fixed gases. 5 naces burning sulfid ores, moistening said In testimony whereof I aflix my signature 15 gases with cold water, depositing solid partiin presence of two witnesses.

cles mechanically carried over with the gases FRANKLIN R. CARPENTER. while they are being cooled and moistened, Witnesses: separating sulfurous oxid from the fixed CRANSTON HOWE CARPENTER,

1o gases by absorbing it in water and refrigerat- FRANK L. GRANT. 

